The present research program is aimed at a better understanding of human brain structure and function, both from a clinical and from a theoretical approach. The experiments have as a major aim, the clarification of normal human neurobehavioral processes, and some pathological symptomatology associated with damaged central nervous tissue. More specifically, some studies examine the nature of normal cerebral lateralization of function, the possible peripheral correlates of this lateralization, and the patterns of dissolution of lateralized perception following unilateral brain damage. In addition, several studies have been initiated in an attempt to define more clearly the perceptual, cognitive and behavioral deficits characteristic of patients with Korsakoff-related brain damage (due to alcoholism), or of patients with brain damage causing lateralized neglect or dementia (e.g., aphasia and Huntington's chorea, respectively). These aims are being implemented by comparing the performance of brain-damaged patients with performance of neurologically intact controls on tests of dichotic auditory perception, concept formation, memory, and information-processing at the threshold level. It is anticipated that the results of these investigations will have relevance for diagnosis, for patient care, for rehabilitation, and for the understanding of basic tenents of human brain function in general.